Improvement in steam-boilers



UNiTED STATES PATENT OFFICE.

EDWARD N. DicKEnsoN, or NEW Yonm'nr.

IMPROVEMENT IN STEAM-BOILERS.

Specification forming part of Letters Patent No. 41,762, dated March l, 1864.

To all whom t may concern,.-

Beit known that I, EDWARD N. DIcKERsoN, of the city, county, and State of New York, have invented a new and useful Improvement in Steam-Boilers for Marine or b'tationary Purposes 5 and I do hereby declare the following to beI a full and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon. v

The nature of my improvement consists in combining in one boiler tubes through which the water passes, and upon the exterior of which the heated gases of combustion impin ge, with tubes through which the heated gases pass in their escape from the boiler, and the exterior of which is enveloped, in whole or in part, by steam, so that the gases, after passing over the water-tubes and imparting to the water their greatest heat, must pass through the steam-tubes, and thereby superheat or dry the steam generated in the water-tubes.

In the accompanying drawings, Figures l and 2 represent a section and front elevation of a marine boiler, drawn to a scale of threequarters of an inch to a foot; and Figs. 3, 4, and 5 represent sections of marine boilers, on the same principle, drawn to a scale of threeeighths of an inch to a foot.

The same letters describe similar parts in all.

Two furnaces are shown in Fig. 2, but of course any desired number maybe collected in one boiler, and they may be of any width. I have made them three feet Wide by six feet deep, as most convenient for working, and because in cleaning res less variation ofsteam is incurred than when larger surfaces are thrown open to the chilling effect of the cold air 5 but of the size of the boilers, constructers must judge for themselves. Fig. 3 shows an arrangement peculiarly adapted to marine uses, as by using two of such boilers set face to face they meet overhead and form the iireroom between them in an arched form, which is very readily made air-tight for blowinginto it.

G G are the grates; L L, the water legs and spaces; W W, the water-tubes through which the water circulates from the lower to the upper part of the boiler, and around which the ames pass, as shown by the red arrows'. By this arrangement of the water-tubes the circulation is forced through the boiler and increases in rapidity with the increased combus tion which may be produced by aforced blast, so that, in effect, more and more water is brought into intimate connection with the heated gases as their quantity and temperature are increased. It is apparent that the greater the amount of steam which is made in the tubes the lighter will be the column of water in the tubes and in the ascending water-back, so as to make the descending water from which the steam has been dischargedheavier in proportion.

S S are the steam-tubes through which the gases pass after comingfrom the water-tubes, and around which the steam circulates, and by which it is superheated.

P P are the steam-pipes which take off the steam from the boiler, and which should be continued the whole length of the boiler, and connected with it by perforations, so that the steam may be drawn uniformly from all parts and over all the steam-tubes. They may be made inside of the boiler, having the shell for at par of them, or otherwise, as desired.

D D are steam doors or plates that may be readily removed, so that both ends of the water-tubes willbe exposed to view and can be cleaned or worked at without going into the boiler.

The exterior ends of the steam-tubes must open into an uptake of some sort, which may be of any materialy or form desired; but I recommend the use of a water-jacket inclosing the uptake, so that the escaping gases may be still further used to evaporate water for any purpose. In boilers like Fig. 1, when two sets are opposite each other byl the distance of a fire-room, a common flue or uptake'may join the two opposite boilers, inclosing the area occupied by the tubes, and thus the products of combustion are carried off; and in these arrangements dampers may be set in the uptake, so that each may cover, when closed, the en ds of the tubes from one furnace, thereby enabling the fireman to shut off the cold draft through the furnace which is being cleaned While the tire-door F may be open. In a marine-boiler the space in the furnace inside of the water-tubes will be large enough to admit a man through a man-hole in the back or through the partitions to come at the lower ends of the steam-tubes, so that three ends of the tubes outof the ve are accessible from Without the boiler, and the remaining ends are easily got at from Within. All the tubes may be drawn and replaced or cleaned Without interfering With each other, Whether the tubes be curved or straight, and all may be cleaned Without any ditculty from either end, which is a result, so far as I know, never yet attained in any boiler havin gWater-tubes nor do I know of any boiler with tubes through which the tire passes so constructed as that the tubes may be approached from both ends Without going into the boiler.

In operation the greater part of the steam is made in the water-tubes and evolved at their upper ends. It there is unable to escape through the steam pipe without passing through the forest of superheating-tubes which interposes between the space where the steam leaves the Water und the steam-pipe, and therefore it will be dried or superheated before it goes to the engine; andin this arrangement I find that the superheating-surfaceof these tubes will be about four times as much for each square foot of grates as can be got by the use of the highest steam-chimney of ordinary construction, While at the saine time the tubular surface Will endure as long as the boiler lasts.

What I claim as my invention, and desire to A EDWI). Nl. DIGKERSON,

Witnesses:

L. PI'rKrN, SAuL. H. CORNWELL. 

